单项选择题
A.pump out B.to pump out C.pumping out D.be pumped out
On a ship，a door that is required to be marked KEEP CLO...
单项选择题On a ship，a door that is required to be marked KEEP CLOSED is designed to（）.
A.prevent the passage of flammable gases B.prevent the passage of poisonous vapors C.delay the spread of heat and flames D.maintain watertight integrity
Limit switches are used on which davits?（）A.Sheath-scre...
单项选择题Limit switches are used on which davits?（）
A.Sheath-screw davits B.Gravity davits C.Radial davits D.Quadrantal davits
In the piping systems of a vessel，what type of valve gi...
单项选择题In the piping systems of a vessel，what type of valve gives the least resistance to fluid flow when fully open?（）.
A.Globe valve B.Butterfly valve C.Gate valve D.Packless valve
